Introduction to battery-management systems- COURSERA WEEK 04 QUIZ -1.4.6 ANSWERS

 

Practice quiz for lesson 1.4.6

Total points 3

1.

Question 1

A battery is built from four series-connected lithium-ion battery cells, where each cell has operational voltage limits $v_{\rm min}=2.5$V and $v_{\rm max}=4.2$V. If the present discharge current limits of the four cells, computed via the HPPC approach, are {94A, 98A, 97A, 96A}, what is the overall battery-pack absolute discharge power capability (in W)? Round your answer to the nearest W and report a positive number.

1 / 1 point

940

Correct

Yes. To compute the battery-pack power, the minimum of the discharge currents must be used.

2.

Question 2

Consider a two-cell series-connected battery pack where cell states of charge are $z_1=0.99$ and $z_2=0.97$ and where the cells have total charge capacity $Q_1=31$Ah and $Q_2=32$Ah. If $z_{\rm min}=0.1$, what is the maximum value for $z_{\rm low}$ (that is, $\max_{j} (z_{{\rm low},j})$) for this battery pack (in percent)? Round your answer to the nearest percent.

1 / 1 point

11

Correct

Yes. You have performed the calculations on slides 2-3 correctly.

3.

Question 3

Consider a two-cell series-connected battery pack where cell states of charge are $z_1=0.99$ and $z_2=0.97$ and where the cells have total charge capacity $Q_1=31$Ah and $Q_2=32$Ah. If $z_{\rm min}=0.1$, and the cells can be considered to have constant OCV of 3.3V, what is the total battery discharge energy for this battery pack (in Wh)? Round your answer to the nearest Wh. (Note that this configuration is the same as in Question 2, which might save you some math.)

1 / 1 point

182

Correct

Yes. You have followed the procedure correctly.